I won't write it for you (don't have the time, sorry), but the module you should look at is
LWP::UserAgent It will allow you to emulate a browser uerying the search engine. You'll have to build up the query string with the requests, but in most cases thats just a case of inserting the search strings into the query string.
Google for example, uses query strings like
http://www.google.com/search?q=blam
to search for 'blam'
Then you'll need to parse your way through the returned page and pull the links to outside pages. Harder, but not too bad. Google for example, looks liek if you pull two lines from each <p> tag you'll get the lines with the details you'll need.
The hardest bit, to my mind? Merging them in a
sensible way. what counts as sensible?